Naval Communication Station Harold E. Holt is a joint Australian and United States naval communication station located on the north-west coast of Australia, 6 kilometres (4 mi) north of the town of Exmouth, Western Australia. The station is operated and maintained by the Australian Department of Defence on behalf of Australia and the United States and provides very low frequency (VLF) radio transmission to United States Navy, Royal Australian Navy and allied ships and submarines in the western Pacific Ocean and eastern Indian Ocean. The frequency is 19.8 kHz. With a transmission power of 1 megawatt, it is claimed to be the most powerful transmission station in the Southern Hemisphere.
Extremely low frequency (ELF) is the ITU designation for electromagnetic radiation with frequencies from 3 to 30 Hz, and corresponding wavelengths of 100,000 to 10,000 kilometers, respectively. In atmospheric science, an alternative definition is usually given, from 3 Hz to 3 kHz. In the related magnetosphere science, the lower-frequency electromagnetic oscillations are considered to lie in the ULF range, which is thus also defined differently from the ITU radio bands.
Super low frequency (SLF) is the ITU designation for electromagnetic waves in the frequency range between 30 hertz and 300 hertz. They have corresponding wavelengths of 10,000 to 1,000 kilometers. This frequency range includes the frequencies of AC power grids. Another conflicting designation which includes this frequency range is Extremely Low Frequency (ELF), which in some contexts refers to all frequencies up to 300 hertz.
Communication with submarines is a field within military communications that presents technical challenges and requires specialized technology. Because radio waves do not travel well through good electrical conductors like salt water, submerged submarines are cut off from radio communication with their command authorities at ordinary radio frequencies. Submarines can surface and raise an antenna above the sea level, or float a tethered buoy carrying an antenna, then use ordinary radio transmissions; however, this makes them vulnerable to detection by anti-submarine warfare forces.
The Strategic Forces Command (SFC), sometimes called Strategic Nuclear Command, forms part of India's Nuclear Command Authority (NCA). It is responsible for the management and administration of the country's tactical and strategic nuclear weapons stockpile. It was created on 4 January 2003 by the Vajpayee Government. Air Marshal Teja Mohan Asthana became its first commander-in-chief.
In radio communication, a ground dipole, also referred to as an earth dipole antenna, transmission line antenna, and in technical literature as a horizontal electric dipole (HED), is a huge, specialized type of radio antenna that radiates extremely low frequency (ELF) electromagnetic waves. It is the only type of transmitting antenna that can radiate practical amounts of power in the frequency range of 3 Hz to 3 kHz, commonly called ELF waves. A ground dipole consists of two ground electrodes buried in the earth, separated by tens to hundreds of kilometers, linked by overhead transmission lines to a power plant transmitter located between them. Alternating current electricity flows in a giant loop between the electrodes through the ground, radiating ELF waves, so the ground is part of the antenna. To be most effective, ground dipoles must be located over certain types of underground rock formations. The idea was proposed by U.S. Dept. of Defense physicist Nicholas Christofilos in 1959.
INS Rajali, is an Indian naval air station located near Arakkonam, Ranipet district, Tamil Nadu in southern India. It operates under the Southern Naval Command of the Indian Navy, and has the longest military runway in Asia.
Project Sanguine was a US Navy project proposed in 1968 for communication with submerged submarines using extremely low frequency (ELF) radio waves. The initially proposed system, hardened to survive a nuclear attack, would have required a giant antenna covering two-fifths of the state of Wisconsin. The proposed approach was never implemented because of protests and potential environmental impact. A smaller, less hardened system called Project ELF consisting of two linked ELF transmitters located at Clam Lake, Wisconsin 46°05′05.6″N90°55′03.7″W and Republic, Michigan 46°20′10.1″N87°53′04.6″W was built beginning in 1982 and operated from 1989 until 2004. The system transmitted at a frequency of 76 Hz. At ELF frequencies, the bandwidth of the transmission was very small, so the system could only send short-coded text messages at a very low data rate. These signals were used to summon specific vessels to the surface to receive longer operational orders by ordinary radio or satellite communication.
Naval Radio Transmitter Facility Aguada is a tall guyed radio mast erected by the United States Navy. It is used as a facility of the US Navy for ashore and U.S. and NATO ships, planes, and submarines operating at sea in areas of broadcast coverage near Aguada, Puerto Rico at 18°23′55″N67°10′38″W by using radio waves in the very low frequency range.
The Minimum Essential Emergency Communications Network (MEECN) is a network of systems providing uninterrupted communications throughout the pre-, trans-, and post-nuclear warfare environment. At minimum, MEECN is designed to provide a one-way flow of information to activate nuclear forces during severe jamming and a post-nuclear environment.
INS Garuda, is an Indian naval air station located in Kochi, in the state of Kerala. Commissioned on 11 May 1953, it is the oldest operating air station of the Indian Navy.
INS Hansa, is an Indian naval air station located near Dabolim in Goa, India. It is India's biggest naval airbase. The military air base has a civil enclave, that operates as Dabolim Airport.
INS Utkrosh, is an Indian naval air station under the joint-services Andaman and Nicobar Command of the Indian Armed Forces. It is located near naval base INS Jarawa, on Port Blair in the Andaman & Nicobar Islands.
INS Parundu is an Indian naval air station located near Uchipuli in the Ramanathapuram of the state of Tamil Nadu. It operates under the Eastern Naval Command of the Indian Navy. The air station will be opened up for civilian flights under Phase 2 of the Regional Connectivity Scheme (RCS) of the Government of India also known as UDAN and the Airports Authority of India (AAI) has started preparatory work at the airstrip. It is sandwiched between Rameswaram National Highway Road and Railway track which leads towards Rameswaram.
INS Varsha is a new naval base being developed under Project Varsha for the Indian Navy. This base will be the home of the navy's new fleet of nuclear submarines and ships. It was planned to be located within a radius of approximately 200 kilometres from Visakhapatnam, the headquarters of the navy's Eastern Naval Command. Previous news reports suggested that Gangavaram had been the initial site for the new base. The base is now being developed at Rambilli, which is 50 km from Visakhapatnam.
INS Baaz is an Indian naval air station under the joint-services Andaman and Nicobar Command (ANC) of the Indian Armed Forces. It is located near Campbell Bay, on Great Nicobar island in the Andaman & Nicobar Islands. It is the southernmost air station of the Indian Armed Forces. It overlooks the Strait of Malacca as well as the Six Degree channel between Great Nicobar and the Indonesian island of Sumatra.
INS Shivaji is an Indian naval station located in Lonavala, Maharashtra, India. It houses the Naval College of Engineering which trains officers of the Indian Navy and the Indian Coast Guard. It was commissioned on 15 February 1945 as HMIS Shivaji. It is located close to the Bhushi Dam. It is located on 876 acres of land.
INS Vajrakosh is a missile and ammunition base of the Indian Navy at Karwar, Karnataka and is the third naval establishment. It was commissioned on 9 September 2015 by the Defence Minister Mr. Manohar Parrikar.
Flag Officer Commanding Tamil Nadu & Puducherry Naval Area (FOTNA) is a senior appointment in the Indian Navy. One of the five Area Commanders of the Indian Navy, the FOTNA is a two star admiral holding the rank of Rear Admiral. The FOTNA is responsible for the operations and administration of all units and establishments in the state of Tamil Nadu and the union territory of Puducherry. The Current FOTNA is Rear Admiral Ravi Kumar Dhingra, VSM, who assumed office on 25 April 2023.
